Such electrode catheters are known in greatly varying embodiments through public prior use, also of the present applicant, and comprise, as the basic components, an elongate, tubular catheter body, at least one electrode for delivering or measuring an electrical, in particular electrocardiac signal, via its external electrode contact surface, at least one first supply line for the electrical connection of this electrode, and at least one second supply line for the electrical connection of a further electrode. These electrodes are typically designed as two ring electrodes seated at the distal end of the electrode catheter with axial spacing, or one ring electrode and one head electrode, via which the stimulus conduction signals of the heart are measured or electrical pulses are delivered, for example, to end or otherwise treat an atrial flutter.
Three different types of supply lines are fundamentally known for the configuration of the electrode supply lines. The first type is the so-called coradial coil, in which the two supply lines are wound parallel to one another, similarly to a thread having two or more pitches, and are insulated from one another. In such coradial coils, the wires are deflected tangentially out of the coil composite and stripped to contact a ring electrode. The wires are then clamped between an inner sleeve and an outer sleeve and crimped or welded.
The connection and passage of the supply lines in such coradial coils has the disadvantage of the fact that tangentially leading the wires out and clamping them between two sleeves requires a comparatively large amount of installation space, which makes the goal of achieving the smallest possible, isodiametrical electrode diameter more difficult. Furthermore, the coil technology is very complex and thus cost-ineffective.
The second type of electrode supply line is the coaxial coil, which has a coiled inner conductor, which leads to a head electrode, for example, and a coiled outer conductor, which leads to a ring electrode situated proximally in front thereof. The coils are connected to the head or ring electrode using welding or crimping. This supply line type has the disadvantage of the fact that because of the two coils seated coaxially one inside the other, achieving the smallest possible electrode diameter in the millimeter range is problematic. This supply line technology can also be practically excluded for multipolar electrotypes.
Finally, a so-called multi-lumen construction is also known as a supply line technology, in which a tubular catheter body has at least two lumens along the electrode catheter. A thin wire cable runs through one of the two lumens to the ring electrode, and a coil is led through the other lumen to a head electrode, for example. The wire cable runs axially oriented to the coil and is welded or crimped to the ring electrode. The coil leads up to the electrode head and is also welded or crimped thereto.
This multi-lumen construction has the disadvantage of the fact that because of the maintenance of minimum wall thicknesses for the external insulation, the design of a multipolar electrode is difficult. Furthermore, the electrode construction is asymmetrical and no redundancy exists for the electrical contact of the ring electrode, because the ring electrode is only connected to the terminal plug via one cable. The durability of the contact between the supply line wire cable and the particular electrode can also be problematic.
U.S. Pat. No. 6,249,708 discloses a multiconductor electrode catheter, in which a central coil is led up to a head electrode and welded thereto. An insulating body is provided around this coil, which is provided with twisted grooves in its peripheral surface. Supply lines for a ring electrode are inserted in each of these. This design is also to be assigned to the coaxial coils having the above-described disadvantages.
U.S. Pat. No. 6,757,970 discloses a multiple electrode catheter, in which the electrode supply lines are led jointly in a multi-lead coil and the ends are led radially out of the coil composite. The contacting of the protruding ends is performed in a complex manner via bending over contact tabs on the strip-shaped ring electrodes, the protruding ends of the supply lines being clamped by the bending over. Subsequently, the strip configuration of the contacts must still be drawn by a tool for rolling into the elongate cylindrical form of the catheter. This design having its specific manner of manufacturing appears extremely difficult with respect to the filigree design of electrode catheters.
Proceeding from the described problems of the prior art, the invention is based on the object of attaching electrode supply lines to a ring electrode, for example, and simultaneously passing through supply lines for further electrodes situated distally to this electrode. Small isodiametrical electrode diameters are achievable through the design, as leading supply lines further to electrodes placed further distal is made more simple and, thus, overall a bipolar or multipolar electrode being able to be implemented using less effort in the contacting.
The present invention is directed at overcoming one or more of the above-identified problems.